Plating tank

ABSTRACT

Provides a plating tank that can transport platy work securely without causing abrasion and attain uniform plating quality and uniform plating film thickness. The shields are comprised of four shielding plates  108, 109, 112,  and  113  on upper part and lower part of the thin plate board as follows. The restrict roller  304  is comprised of the roller stand body  120  which reaches until nearly upper end area&#39;s height of thin plate board and stood on upper face of the lower shielding plates  108,  and the work-end deviation preventing member  122.

CROSS REFERENCE TO RELATED APPLICATIONS

The entire disclosure of Japanese Patent Application No. 2005-300255including specification, claims, drawings and summary are incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the skill which is used forelectroplating a platy work, for example printed board etc., by asurface treatment device like an electroplating device.

BACKGROUND ART

A conventional surface treatment device like an electroplating devicetreats a platy work which is secured to a rack as to transfer withoutswinging. However, the surface treatment device of rackless type issuggested, because it is bothering task to mount the platy work in therack and it is so large load that the device grows in size.

As a surface treatment device of rackless type like this, Japanese LaidOpen Patent Application No. 2002-363796 (Patent Document 1) is known.Referring to FIG. 14 and FIG. 15, the structure of the surface treatmentdevice will be described as follows. FIG. 14 shows plane view of thesurface treatment device 300 from upside. FIG. 15 shows side view of thesurface treatment device 300 from α-direction.

As shown in FIG. 14 and FIG. 15, the surface treatment device 300 is thesurface treatment device of so-called pusher type, and has guide rails10-13 for transporting the transport hanger 15 which is holding theplaty work such as a printed board. Along with these guide rails 10-13,the surface treatment device 300 has the pre-treatment tank 1 of eachtype for processing before plating, plating tank 2 for electroplating,recovery tank 3 and water-washing tank 4 for processing after plating,unload section 5 for unloading the platy work, exfoliate tank 6 forseparating plating films (hanger restoring process), water-washing tank7 for water-washing the transport hanger 15 after separating, and loadsection 8 for loading a board.

As rise-and-fall guide rails 10, 12 shown in FIG. 14 falls, the platywork W is dipped into various tanks (e.g., plating tank 2, exfoliatetank 6, water-washing tank, and hot water-washing tank, cleaner tank,etc.). Also, when Rise-and-fall guide rails 10, 12 are fallen as shownin FIG. 15, guide rails 10-13 configure one circular guide rail.

By falling of rise-and-fall guide rails 10, 12 shown in FIG. 14, theplaty work W is guided into treatment liquids on a dipping position ((x)position of FIG. 14) of the plating tank 2. The platy work W dipped intotreatment liquids is transferred inside the platy tank 2.

The transport hanger 15 used for the surface treatment device 300 of theabove-mentioned so-called pusher type, as shown FIG. 9, hastreating-object holding member 47 with plural clamps 48 for holding theplaty work W, slide member 35 which contact slidably with guide railssuch as fixed guide rail 11, and connecting members 44 for connectingsuch members. The transport hanger 15 holds the upper end of the platywork W by clamp 48.

For the purpose to achieve uniform plating quality or uniform platingfilm thickness, the surface treatment device 300 of pusher type like theabove-mentioned treats the platy work W by spouting jet flow oftreatment liquids to the platy work W from spouters arranged both sidesof the platy work W inside the platy tank. However, because it doesn'tuse the rack, the plating film thickness of platy work W becamenon-uniform as the platy work W swings when transporting and thedistance to electrode is not constant, or the plating film thickness ofthe edge of the platy work became thicker unusually because currentconcentration has occurred on the edge of the platy work.

Therefore, it is big issue to be solved for the surface treatment deviceof rackless type to restrict swinging of the platy work and not to occurcurrent concentration on the edge of the platy work W.

Consequently, the above-mentioned Patent Document 1 discloses intervalbetween adjacent platy works of back-and-forth is adjusted byfast-forwarding until it becomes predetermined distance (for example, 50mm) inside the plating tank 2 to prevent from occurring currentconcentration on the back-and-forth end of the platy work W.Additionally, a linear guide made of Teflon (registered trademark) isattached inside of a surface treatment tank such as a plating tank forpreventing the platy work W from swinging, or a shielding plate isattached for preventing from occurring current concentration on the edgeof the platy work W (Refer to the Japanese Laid Open Patent ApplicationsNo. 2000-178784 (Patent Document 2) and No. 2002-13000 (Patent Document3)).

Moreover, when the printed board (thickness is below 0.1 mm) is used asthe platy work (hereinafter referred to as thin plate board), it issuggested that leading guide etc. as shown in FIG. 16 is arranged insidea tank for the purpose of dipping the platy work W smoothly into eachtreatment tank (Refer to the Japanese Laid Open Patent Applications No.2004-346391 (Patent Document 4).

The leading guide of Patent Document 4 is comprised of a pair ofcommutate members 131 (slant down flow boards 131 a, 131 b) placed atfalling position of the thin plate board. As shown in FIG. 16, the slantdown flow boards 131 a, 131 b are formed its upper side like as V style.And spouting tubes 132 are arranged along upper end area of the slantdown flow boards 131 a, 131 b. Further, a liquid suction tube 133 isarranged on lower part of the slant down flow boards 131 a, 131 b, whichaspirates plating liquids and spouts it from the spouting tubes 132.Therefore, it becomes possible to guide the thin plate board promptlywith the flow on the lower side spouting from the slant down flow boards131 a, 131 b.

However, the above-mentioned conventional art can't achieve uniformplating quality by jet flow of plating liquids or uniform plating filmthickness by preventing from occurring current concentration on theupper and lower end of the platy work W, though it was possible toprevent current concentration on the back-and-forth end of platy works.

For instance, although Patent Documents 2 and 3 discloses that a louveris used for achieving uniform plating quality by commutating the jetflow of plating liquids, the plating efficiency or plating quality mayget worse as it may occur excessive current shielding effect in somecases. Also, although shielding plate is arranged on the lower end ofthe platy work W, enough effect was not attained because currencydetouring occurs in some cases. Thus, it is likely to vary platingthickness as occurring current concentration on the upper and lower endof the platy work W.

Further, although a linear guide made of Teflon is used for preventingthe platy work W from swinging, linear shaped Teflon was easily to breakaway by touching with platy work W. Therefore, sometimes it is notprevented platy work W from swinging. Further, although it is possibleto add metal wire as a core member to the linear guide made of Teflon,when plastic Teflon is broken away and metal wire became exposed, it wascaused abrasion on the platy work W by touching with exposed metal wire,and plating quality became worse because the plating adhered to themetal wire is mixed in treatment liquids. Especially, when the thinplate board (thickness is below 0.1 mm) is used, it is subject to swingand twist easily because of plating jet flow. And it is subject to causeabrasion as transporting slidably with platy work W.

SUMMARY OF THE INVENTION

As to solve the above problems, an object of the present invention is toprovide a plating tank used for a surface treatment device such as aelectroplating device (especially, for the electroplating device whichtransports a platy work such as printed board in holding vertically)which can transport platy work such as thin printed board (thickness isbelow 0.1 mm) securely without causing abrasion, and attain uniformplating quality and uniform plating film thickness.

A plural of Independent aspects of the present invention will beindicated as follows.

(1) In accordance with characteristics of the present invention, thereis provided a plating tank comprising:

a treatment tank main body for holding treatment liquids which isarranged as extending in transporting direction of the platy work;

a positive electrode;

a spouter for spouting the treatment liquids to the said platy work fromlateral side of the treatment tank main body;

a restrict roller having a plural of rollers, wherein the rollers areattached rotatably from upper part until lower part of the treatmenttank main body and arranged consecutively in transporting direction ofthe platy work as sandwiching both sides of the platy work on movinginside the treatment tank main body;

a current shield for preventing from occurring current concentration onthe end of the platy work.

Therefore, it becomes possible to maintain upright state of the thinplate board W by restrict roller. Also, it doesn't cause abrasion asroller is used. It becomes possible to treat uniformly.

(2) In accordance with characteristics of the present invention, thereis provided a plating tank:

wherein the said restrict roller is comprised of a plural of rollerstand bodies which are having plural rollers vertically, and arranged intransporting direction of the said plating work, and interval on thespouting position of the spouter between adjacent roller stand bodiesare wider than the other intervals.

Therefore, it becomes possible to provide treatment liquids with platywork (especially, thickness is below 0.1 mm) uniformly by spouter, andit becomes possible to maintain upright state of the thin plate board Wby restrict roller. Also, it doesn't cause abrasion as roller is used.It becomes possible to treat uniformly.

(3) In accordance with characteristics of the present invention, thereis provided a plating tank:

wherein a deviation preventing member is placed at lower end area of theplaty work where the spouting position of the spouter is placed assandwiching both sides of the platy work on moving.

Therefore, it becomes possible to prevent from bending on the lower endof platy work (especially, thickness is below 0.1 mm) properly.

(4) In accordance with characteristics of the present invention, thereis provided a plating tank:

wherein the rollers are arranged at least one per predetermined unitarea in a region that the restrict rollers are arranged.

Therefore, it becomes possible to prevent from swinging or twisting ofplaty work (especially, thickness is below 0.1 mm) in transportingdirection or vertical direction and to maintain intervals between platywork and positive electrode constantly. It becomes possible to attainuniform of plating film thickness.

(5) In accordance with characteristics of the present invention, thereis provided a plating tank:

wherein the said restrict roller is comprised of a plural of rollerstand bodies which are having plural rollers vertically, and arranged intransporting direction of the said plating work, and vertical intervalsthat the rollers of the restrict roller is arranged are range from 50 mmto 100 mm.

Therefore, it becomes possible to prevent from swinging or twisting ofplaty work (especially, thickness is below 0.1 mm) in transportingdirection or vertical direction and to maintain upright state. Itbecomes possible to maintain intervals between platy work and positiveelectrode constantly and to attain uniform of plating film thickness.

(6) In accordance with characteristics of the present invention, thereis provided a plating tank:

wherein the said restrict roller is comprised of a plural of rollerstand bodies which are having plural rollers vertically, and arranged intransporting direction of the said plating work, and the rollers placedover predetermined height differs the vertical position mutually betweenthe roller stand bodies.

Therefore, it becomes possible to prevent from causing electricalshielding effect at same height. It becomes possible to prevent fromoccurring unevenness of plating and to attain uniform plating.

(7) In accordance with characteristics of the present invention, thereis provided a plating tank:

wherein the said current shield is comprised of a upper shielding platefor preventing from occurring current concentration on the upper end ofthe platy work and/or a lower shielding plate for preventing fromoccurring current concentration on the lower end of the platy work.

Therefore, it becomes possible to prevent current concentration on bothupper and lower end of platy work. It becomes possible to attain uniformof plating film thickness.

(8) In accordance with characteristics of the present invention, thereis provided a plating tank:

wherein the said upper shielding plate and/or the lower shielding plateare comprised of plural shielding plates arranged between the said platywork and the said positive electrode, and its overlap with the platywork is the smaller, the closer to the platy work.

Therefore, it becomes possible to prevent from detouring of currency byshielding plate. It becomes possible to attain uniform of plating filmthickness even if the shielding area of platy work is small. Also, it ispossible to enhance productivity as gaining enough current shieldingeffect without decreasing current value.

(9) In accordance with characteristics of the present invention, thereis provided a plating tank:

wherein the said plurality of shielding plates are formed in a unifiedmanner and able to rise and fall.

Therefore, it becomes possible to attain uniform of plating filmthickness even if the size of platy work is varied.

The other aspects of the present invention will be indicated as follows.

(a) In accordance with characteristics of the present invention, thereis provided a platy work dipping device, comprising:

a treatment tank for dipping a platy work into treatment liquids;

a board guide for guiding platy board falling into the treatment tankhaving a upper guide board and a lower guide board, wherein the lowerguide plate is arranged parallel spacing predetermined distance andupper board guide is arranged like taper as widening toward upsidevertically and having slit of cutout, and a tip of upper board guide isprojecting from fluid level and dipping its slit into plating liquids;

a liquid current generator arranged outside the said board guide.

Therefore, it becomes possible to guide a platy work smoothly alongboard guide, as liquid flow from outside of board guide can be led todownward inside the board guide through cutout. Especially, if treatmentliquids are acid cleaner including fizzy material like surface-activeagent, it is possible to prevent deterioration in plating quality whichcause by bubble generated on fluid level and to guide platy boardsmoothly.

(b) In accordance with characteristics of the present invention, thereis provided a platy work dipping device:

wherein the liquid current generator is sparger for spouting jet flowagainst the said cutout nearly in a horizontal direction, orair-bubbling tube arranged at nearly middle height inside the treatmenttank.

Therefore, it becomes possible to guide a platy work smoothly alongboard guide, as liquid flow from sparger can be led to downward insidethe board guide through cutout without occurring bubble on fluid levelinside the board guide.

(c) In accordance with characteristics of the present invention, thereis provided a platy work dipping device:

wherein the liquid current generator is sparger for spouting jet flowtoward upper part than the said cutout in upper direction against ahorizontal direction.

Therefore, it becomes possible to guide a platy work smoothly alongboard guide, as liquid flow from sparger toward upper part in upperdirection against a horizontal direction can be led to downward insidethe board guide through cutout without occurring bubble on fluid levelinside the board guide.

(d) In accordance with characteristics of the present invention, thereis provided a platy work dipping device:

wherein liquid current generator is air-bubbling tube discharging airupwards.

Therefore, it becomes possible to guide a platy work smoothly alongboard guide by simple structure, as liquid flow from air-bubbling tubewhich discharging air upwards can be led to downward inside the boardguide through cutout without occurring bubble on fluid level inside theboard guide.

(e) In accordance with characteristics of the present invention, thereis provided a platy work dipping method for guiding a platy work fallinginto the treatment body by using a board guide:

projecting a tip of upper board guide from fluid level and dipping itsslit into plating liquids;

generating by liquid current generator arranged outside the said boardguide and under fluid level;

falling and dipping a platy work into treatment liquids.

Therefore, it becomes possible to guide a platy work smoothly alongboard guide, as liquid flow from outside of board guide can be led todownward inside the board guide through cutout. Especially, if treatmentliquids are plating liquids, it is possible to prevent deterioration inplating quality which cause by bubble generated on fluid level and toguide platy board smoothly.

The characteristics of the present invention are broadly indicated asnoted above, but structure, contents, object, and features will be clearthough reference to the figures and according to the followingdisclosure.

BRIEF DESCRITION OF THE DRAWINGS

FIG. 1 shows α-α cross-section of plating tank 2 (FIG. 14).

FIG. 2 shows the structure of inside plating tank 2 from β-direction ofFIG. 1.

FIG. 3 shows plane view of plating tank 2 from γ-direction of FIG. 1.

FIG. 4 shows detail structure of roller stand body from β-direction ofFIG. 1.

FIG. 5 shows detail structure of deviation preventing member 122 (122 a,122 b).

FIG. 6 shows detail structure of board dipping device 600.

FIG. 7 shows perspective view of board guide 62.

FIG. 8 shows detail structure of jet nozzle 64.

FIG. 9 shows detail structure of the transport hanger 15.

FIG. 10 shows cross-section near the center of the transport hanger 15.

FIG. 11 shows plane view of intermittent transporter 17 on therise-and-fall guide rail 10.

FIG. 12 shows the structure of positioning transporter 18.

FIG. 13 shows the structure of board dipping device.

FIG. 14 shows plane view of surface treatment device 300 from upside.

FIG. 15 shows side view of surface treatment device 300 fromα-direction.

FIG. 16 shows the structure of conventional leading guide.

FIG. 17 shows the structure of spouter 302.

FIG. 18 shows the structure of shields (shielding means) 303.

FIG. 19 shows view of support connecting member 216 from thin plateboard W's side.

FIG. 20 shows the structure of positive electrode 102.

FIG. 21 shows overlapping range of thin plate board W and shieldingplate.

FIG. 22 shows the structure of roller stand body 120's lower part.

FIG. 23 shows the view of swinging board W from transporting direction.

FIG. 24 shows the view of swinging board W from upside of plating tank.

FIG. 25 shows the structure of roller stand body 120's upper end.

FIG. 26 shows relationship between number of roller 116 andpredetermined area of thin plate board W to be transported.

DETAILED DESCRIPTION OF DESIRED EMBODIMENTS

1. Plating Tank

The basic structure of the surface treatment device is the same as shownin FIG. 14 and FIG. 15. FIG. 14 shows plane view of surface treatmentdevice 300 from upside. FIG. 15 shows side view of surface treatmentdevice 300 from α-direction.

As shown in FIG. 14 and FIG. 15, the surface treatment device 300 is thesurface treatment device of so-called pusher type, and having guiderails 10-13 for transporting the transport hanger 15 which is holdingthe platy work such as a printed board, and arranged such that alongthese guide rails 10-13, the pre-treatment tank 1 of each type forprocessing before plating, plating tank 2 for electroplating, recoverytank 3 and water-washing tank 4 for processing after plating, unloadsection 5 for unloading the platy work, exfoliate tank 6 for separatingplating films (hanger restoring process), water-washing tank 7 forwater-washing the transport hanger 15 after separating, and load section8 for loading a board.

As rise-and-fall guide rails 10, 12 shown in FIG. 14 falls, the platywork W is dipped into various tanks (e.g., pre-treatment tank 1, platingtank 2, recovery tank 3 and water-washing tank 4, and exfoliate tank 6).Also, when Rise-and-fall guide rails 10, 12 has fallen as shown in FIG.15, guide rails 10-13 configure one circular guide rail.

FIG. 1 shows α-α cross-section of plating tank 2 (FIG. 14) as oneembodiment of the present invention. A treatment tank main body 100(including after-mentioned overflow tank 202, drain 200) is holdingtreatment liquids. The thin plate board W (platy work), which is to betreated in the treatment tank main body 100 filled with treatmentliquids, is held and hung by clamping of the transport hanger 15 on itsupper end. By transferring the transport hanger 15, the thin plate boardW also moves inside the treatment tank main body 100.

The treatment tank main body 100 is comprised of positive electrode 301for supplying metal ion of electroplating, spouter 302 for spoutingtreatment liquids toward the thin plate board W, shielding means 303 forshielding currency not to occur current concentration on the edge of thethin plate board W, restrict roller 304 arranged as sandwiching the thinplate board W for keeping the thin plate board W on standing state whenmoving in the treatment tank main body 100. Furthermore, the concretestructure of the positive electrode 301, the spouter 302, the shieldingmeans 303, the restrict roller 304 will be described as follows.

The positive electrode 301 is comprised of a pair of positive electrodes102, 104 which is arranged plenty with keeping a predetermined intervalalong transporting direction of the thin plate board W, and power supplyrail 224 which is arranged in the treatment tank main body 100 alongtransporting direction of the thin plate board W for suspending andenergizing positive electrodes 102, 104 shown in FIG. 1.

The spouter 302 is comprised of eductor box 204 for equalizing pressureof plating liquids, a pair of spargers 106 for spouting plating liquidsfrom both sides of the thin plate board W at nearer position to the thinplate board W than positive electrodes 102, 104, pipe 210, andcirculation pump 208 for returning plating liquids through the pipe 210to the eductor box 204 after filtering discharged through drain 200 oroverflow tank 202 by barrier filter shown in FIG. 1.

The shielding means 303 is comprised of following four shielding platesshown in FIG. 1. The lower board shielding plates 108 are arranged withfacing at lower end of the thin plate board W close to the thin plateboard W along transporting direction of the thin plate board W. On theother hand, the upper board shielding plates 109 are arranged withfacing at upper end of the thin plate board W close to the thin plateboard W along transporting direction of the thin plate board W as well.Also, between positive electrode 102, 104 and sparger 106, the lowerelectrode shielding plate 112 is arranged around lower end area ofpositive electrode 102, 104 and the upper electrode shielding plate 113is arranged around upper end area of positive electrode 102, 104 closeto positive electrode 102, 104 along transporting direction of the thinplate board W respectively. Also, the shielding means 303 has a heightadjuster 220 for adjusting height of lower board shielding plates 108and lower electrode shielding plate 112 based on size of the thin plateboard W. Left side of FIG. 1 indicates lowered condition correspondingto large sized thin plate board W and right side of FIG. 1 indicatesheightened condition corresponding to small sized thin plate board W.

The restrict roller 304 is comprised of the roller stand body 120 whichreaches until nearly upper end area's height of thin plate board andstood on upper face of the lower shielding plates 108, and the work-enddeviation preventing member 122. The restrict roller 304 is possible toadjust a height based on size of the thin plate board W with lower boardshielding plates 108 and lower electrode shielding plate 112 by theabove-mentioned height adjuster 220.

The roller stand body 120 is comprised of shaft 114 which stands on thelower board shielding plate, and roller 116 which is attached verticallyon the shaft 114 and rotatably. Also, it is possible to secure theroller 116 to shaft 114 and to rotate itself the shaft 114.

Concretely, as shown in FIG. 4 that shows detail structure of rollerstand body from β-direction of FIG. 1, the roller stand body 120 has theroller 116 formed by PP (Polypropylene) resin, and adjusting member 116e which adjust each distance between upper and lower rollers by puttingshaft 114 to each insert hole and intermediating between upper and lowerrollers. Further, securing member 116 g is attached around upper endarea of the shaft 114 for the roller 116 and the adjusting member 116 enot to be tripped.

As shown in FIG. 25, the securing member 116 g is attached as spacingclearance (L70) from upper end of top roller 116. Therefore, as theroller 116 can float in plating liquids, it will be prevented fromrotating improperly based on scratching between each roller 116 andadjusting member 116 e, and further be prevented from causing abrasionbased on contact between the thin plate board W and roller 116.

FIG. 2 shows the structure of inside plating tank 2 from β-direction ofFIG. 1. It is indicated that a number of the roller stand body 120 isarranged toward transporting C-direction of the thin plate board W.

FIG. 3 shows plane view of plating tank 2 from γ-direction of FIG. 1.The thin plate board W is transported between facing roller stand bodies120. Thus, the thin plate board W is transported with right state(maintaining upright state) because the roller 116 of roller stand body120 restricts the thin plate board W. By the way, the restrict roller304 has roller stand body 120 and roller 116 for maintaining uprightstate (right state) as shown below.

First, the arrangement of the roller stand body 120 will be described.As shown in FIG. 22, facing roller stand bodies 120 are arranged as thedistance L40 between roller 116 and thin plate board W becomes from 1 mmto 5 mm (e.g., this case is 4 mm). If the distance is below 1 mm, it maycause abrasion on surface of the thin plate board W as the roller 116contacts with thin plate board W. Also, if the distance is over 5 mm, itmay cause non-uniform of plating film thickness as the thin plate boardW is distorted vertically.

Also, intervals L3 between roller stand body 120 are wider than theother intervals L2 at the position where sparger 106 is placed(indicated as N in FIG. 4) in this embodiment. Interval L3 is lager thandiameter of the roller 116 at the position N where the sparger 106 isplaced in this embodiment. Interval L2 is smaller than diameter of theroller 116 at the other position. Therefore, it is possible to spreadjet flow of plating liquids on the thin plate board W effectively as theroller stand body 120 doesn't interfere with jet flow of plating liquidswhich is discharged by the sparger 106.

However, because of the said large intervals L3, it may be causedbending of the thin plate board W at the position based on jet flow ofthe sparger 106, or incomplete transporting as bent part intrudesbetween the roller stand bodies 120. Therefore, deviation preventingmember 122 a is placed at lower part of the roller stand body 120, anddeviation preventing member 122 b is placed at middle height of theroller stand body 120 in this embodiment. Especially, it is importantthat the deviation preventing member 122 a, which is for preventinglower end of the thin plate board W from bending, is placed at lower endpart.

FIG. 5 shows detail structure of deviation preventing member 122 (122 a,122 b). FIG. 5A shows plane view, and FIG. 5B shows side view. As shownin FIG. 5, deviation preventing member 122 a is obviously secured tolower part of shaft 114 (0-50 mm from top face of the lower boardshielding plate 108, especially in the range of 0-20 mm: 5 mm, in thiscase). While the roller 116 is attached rotatably, the deviationpreventing member 122 a doesn't rotate. Also, as shown in FIG. 5A,transporting space 124 of the thin plate board W is formed betweenfacing deviation preventing members 122 a. In this way, it is preventedfrom that bent part intrudes between the roller stand bodies 120, orthat deviates from lower board shielding plate 108. Furthermore, thestructure of deviation preventing members 122 b is same as deviationpreventing members 122 a.

Next, the arrangement of the rollers will be described. As shown in FIG.26 in the region that 10-12 units of roller stand bodies 120 arearranged, there is at least one roller per predetermined unit area (e.g.100 mm×100 mm). The region that the roller stand bodies 120 are arrangedmeans region viewed where the roller stand bodies 120 are arranged in atransporting direction of the thin plate board W from a directionperpendicular to the transporting direction on as shown in FIG. 26. Onthe region, it is possible to reduce swinging of the thin plate board Weffectively, by arranging at least one the rollers 116 for restrictingswing per predetermined unit area against the thin plate board W in theregion. The reason why based on this per predetermined unit area forarranging roller is to restrict both swings toward transportingdirection and vertical direction. Furthermore, predetermined unit areais desirable up to 100 mm×100 mm.

Therefore, it becomes possible to prevent non-uniform plating filmthickness occurring from that the thin plate board W loses erectness byjet flow of plating liquids and a distance from positive electrode 102,104 changes as shown in FIG. 23 and 24. And, it becomes possible toprevent incomplete transport occurring from that the tip of thin plateboard W swings and intrudes between the roller stand bodies 120.Furthermore, FIG. 24 shows the view of swinging board W from upside ofplating tank.

Vertical intervals between adjacent rollers 116 of the roller standbodies 120 are 50-100 mm. The vertical Intervals mean the intervals ofcircular plates of rollers 116 (L30 shown in FIG. 4). If it is below 20mm, the rollers 116 cause electrical shielding effect against the thinplate board W, and it may be caused non-uniform plating film thickness.On the other hand, if it is over 100 mm, thin plate board W is bentbetween rollers 116 and lose erectness, and it may be caused non-uniformplating film thickness by varying a distance of the thin plate board Wto the positive electrode 102, 104 vertically and locally as shown inFIG. 23. Furthermore, FIG. 23 shows the view of swinging board W fromtransporting direction.

Further, FIG. 4 shows arranging condition of the roller stand body 120.In the arrangement of plural roller stand bodies 120, the roller standbodies 120 of 10-12 numbers arranged in transport direction of thinplate board W are forming one unit, and the height of each roller 116 isdifferent from the others. For example, there is no roller which is sameheight H as roller 116 a of center area (at predetermined height: forexample, at higher position over 50 mm from lower end of the platywork). There is no roller which is some height as the others. This isfor the reason that linear unevenness of plating is not to be formed onthin plate board W by contacting with roller 116 at same height, and theplating film thickness on the surface of thin plate board W is not to begetting thinner by forming electrical shadows of the roller 116 at sameheight part.

However, the rollers on lower part of the roller stand bodies 120, below50 mm from top face of lower board shielding plate 108, are allowed tobe positioned at same height. The bottom roller 116 b of the rollerstand bodies 120 is arranged at below 50 mm, especially below 20, fromtop face of lower board shielding plate 108. This is for the reasonthat, the lower end of thin plate board W is raised, if the thin plateboard W loses erectness by jet flow of plating liquids as shown in FIG.23. As the bottom roller is arranged as closer as possible to the lowerend of the thin plate board W, it is prevented that the lower end of thethin plate board W deviates from clearance formed by lower boardshielding plate 108.

As mentioned previously, the roller stand body 120 is formed standing onthe lower board shielding plate 108, and moves up and down with thelower board shielding plate 108 integrally. Therefore, the positionalrelationship between lower board shielding plate 108 and bottom roller116 b of roller stand body 120, or deviation preventing member 122 adoesn't change if the height is adjusted based on size of the thin plateboard W. The simple structure makes it possible to be operated againstvarious sized thin plate board W in the same way.

Thus, the restrict roller 304 in this embodiment regulates five elementsto improve quality of electroplating, and the arrangement of roller 116is determined. That is, the arrangement of roller 116 is determined for(i) keeping upright condition of the thin plate board W, (ii) reducingcurrent shield effect by roller 116, iii), keeping effect of plating jetflow by spouter iv) preventing incomplete transport occurring from thatthe thin plate board W intrude between roller stand body 120, v)preventing from causing abrasion by roller 116.

Concretely, to establish the above (i) the roller 116 is arranged atleast one per predetermined unit area (e.g. 100 mm×100 mm) basically.Further, a distance between roller 116 and thin plate board W isdetermined as range 1-5 mm (below 5 mm) and a interval between verticalrollers 116 is determined as range 50-100 mm (below 100 mm) to restrictvertical deflection of the thin plate board W more effectively. Toestablish the above (ii), a interval between vertical rollers 116 isdetermined as range 50-100 mm (over 50 mm), and the rollers 116 placedover predetermined height differs the vertical position mutually betweenthe roller stand bodies 120 of 10-12 numbers. To establish the above(iii), intervals L3 between roller stand body 120 are wider than theother intervals at the position where sparger 106 is placed. Toestablish the above (iv), the rollers on lower part of the roller standbodies 120 are allowed to be positioned at same height, and deviationpreventing member 122 a is placed where the roller stand bodies 120 arearranged spacing the above intervals L3, and the roller stand body 120where sparger 106 is not placed is spaced Interval L2 which is smallerthan diameter of the roller 116. Lastly, to establish the above (iv),the securing member 116 g secures as spacing clearance from upper end oftop roller 116 and thin plate board W is determined as range 1-5 mm(over 1 mm).

Although each combination of them can be selected accordingly, it isdesirable to be provided entirely.

FIG. 17 shows the structure of spouter 302 excluding positive electrode301, restrict roller 304 and shielding means 303. As shown in FIG. 17,spouter 302 spouts treatment liquids by sparger 106 toward the thinplate board W.

Plating liquids spouted from sparger 106, is discharged from thetreatment tank main body 100 through drain 200 or overflow tank 202, andreturns to eductor box 204 by circulation pump 208 through the pipe 210after filtering by barrier filter 209, and returns to sparger 106 againas circulating after equalizing pressure of plating liquids in eductorbox 204.

Plural eductor boxes 204 are arranged on the bottom of the treatmenttank main body 100 along transporting direction of the thin plate boardW. As shown in FIG. 17, eductor boxes 204 are bolted on the bottom plateof the treatment tank main body 100 as height adjustable. On the sideplate of eductor box 204, connecting hole is formed and pipe 210 isconnected for transferring liquids. Also, support member 204 a isattached to the eductor box 204, which prevents that it becomesimpossible to equalize pressure of plating liquids by changing shapebased on pressure of plating liquids transferred from circulation pump208.

As shown in FIG. 17, spargers 106 is formed by attaching plural jetnozzles 106 a for spraying plating liquids to nozzle tube 106 b withspacing predetermined intervals. The nozzle tube 106 b is stood oneductor box 204, and eductor box 204 and lower end of nozzle tube 106 bare connected through connecting hole for transferring liquids. On theother hand, upper end of the sparger 106 is fit in hole formed on thenozzle fixing member which is attached along transporting direction ofthe thin plate board W. Therefore, jet flow of plating liquids againstthe thin plate board W is constant, as the sparger 106 is prevented fromleaning (tumbling) to the opposite side of the thin plate board W orfrom vibrating by spouting pressure when spouting plating liquids.

As shown in FIG. 17, jet nozzle 106 a of spargers 106 are arranged atalternate height between right side and left side of the thin plateboard W. This is to make difference in jet pressure of plating liquidson the thin plate board W and to realize flow transferring insidethorough-hole formed on the thin plate board W.

FIG. 18 shows the structure of shielding means 303 excluding positiveelectrode 301 and a portion of spouter 302. As shown in FIG. 18,shielding means 303 is comprised of upper board shielding plates 109,upper electrode shielding plate 113, lower board shielding plates 108,and lower electrode shielding plate 112 having a rolling mechanism,plate 110 and support connecting member 216 for connecting lower boardshielding plates 108 and lower electrode shielding plate 112 integrally,height adjuster 220 for elevating lower board shielding plates 108 andlower electrode shielding plate 112 integrally, and guide table 214 forguiding lower electrode shielding plate 112 when adjusting height, andpole 155.

As shown in FIG. 18, upper board shielding plates 109 and upperelectrode shielding plate 113 are attached to nozzle fixing member 212.The upper board shielding plates 109 and the upper electrode shieldingplate 113 are height adjustable up and down in drawing respectively,because of having long hole of up and down direction in drawing andbolting on nozzle fixing member 212 through the long hole.

In this way, upper board shielding plates 109 and upper electrodeshielding plate 113 are used at the same time, because it is desirableto shield currency effectively at minute area such as 1-5 mm from edgeof the thin plate board W. By using upper board shielding plates 109,current concentration on upper end of the thin plate board W iscontrolled locally. The upper electrode shielding plate 113 controlscurrency, that upper board shielding plates 109 couldn't controladequately, not to detour around upper end of the thin plate board W.

Also, as shown in FIG. 18, shielding plate of the thin plate board W'slower end having the lower board shielding plates 108 and the lowerelectrode shielding plate 112 to prevent from current concentration onthe thin plate board W's lower end in this embodiment. The reason usinglower board shielding plates 108 and lower electrode shielding plate 112at the same time is same as the above-mentioned reason of upper boardshielding plates 109 and upper electrode shielding plate 113.

The overlap L60 of shielding plates 108, 109, 112, 113 from edge of thethin plate board W (overlapping length between thin plate board W andshielding plate shown in FIG. 21: hereinafter referred to as overlaplevel) is set the smaller, the closer to the thin plate board W. Forinstance, lower board shielding plate 108, which is more closer to thethin plate board W, is set overlap level smaller than lower electrodeshielding.

It is desirable that distance L50 (FIG. 22) of board shielding plates108, 109 from the thin plate board W is range 1-50 mm. Therefore, it ispossible to prevent from occurring current concentration on the edge ofthe platy work W effectively without reducing amount of energizationrequired in plating (without reducing plating effectiveness).

Concretely, the upper board shielding plates 109 is overlapped 1-15 mm(10 mm in this embodiment) against upper end of the thin plate board W.The upper electrode shielding plate 113 is overlapped 10-60 mm (50 mm inthis embodiment) against upper end of the thin plate board W. Also, theupper board shielding plates 109 (tip of L shaped bottom) is arranged 25mm distance from the thin plate board W.

On the other hand, the lower board shielding plates 108 is overlapped1-10 mm (5 mm in this embodiment) against lower end of the thin plateboard W. The lower electrode shielding plate 112 is overlapped 50-75 mm(65 mm in this embodiment) against lower end of the thin plate board W.Also, the lower board shielding plates 108 is arranged 4 mm distancefrom the thin plate board W.

By the way, the effect of shield currency changes, if the setting ofoverlapping level between board shielding plate and electrode shieldingplate has changed. Therefore, as the above-mentioned, lower boardshielding plates 108 and lower electrode shielding plate 112 areadjustable of height by height adjuster 220 integrally not to change theoverlap level between board shielding plate and electrode shieldingplate, even if the size of the thin plate board W has changed.

In FIG. 18, lower board shielding plates 108 is attached on the plate110, and the plate 110 is connected to the lower electrode shieldingplate 112 through support connecting member 216, and lower boardshielding plates 108 and lower electrode shielding plate 112 are formedintegrally. Furthermore, the support connecting member 216 is also fixedon upper face of the lower board shielding plates 108 for preventingdeflection of plate 110.

As shown in FIG. 18, guide table 214 for guiding lower electrodeshielding plate 112 is attached on the bottom plate of the treatmenttank main body 100 as housing the above eductor box 204 on its downward.Poll 155 is stood upside of guide table 214, and its upper end is boltedon nozzle fixing member 212. The lower electrode shielding plate 112 isbolted (not illustrated) movably up and down through vertical long holeagainst guide table 214, and rolling mechanism 150 arranged on lowerelectrode shielding plate 112 fits in pole 155 movably up and downthrough roller 150 a. In this way, as the lower electrode shieldingplate 112 is guided by guide table 214 and poll 155, lower boardshielding plates 108 and lower electrode shielding plate 112 and rollerstand body 120 are guided integrally when adjusting height by heightadjuster 220.

In FIG. 18, height adjuster 220 is comprised of driving motor 220 a,pulley 220 b, connecting wire 220 c, driving belt 220 d, and one end ofthe connecting wire 220 c is fixed to pulley 220 b and other end isconnected to support connecting member. As wire 220 c is rolled up bypulley 220 b based on driving of driving motor 220 a, lower boardshielding plates 108 and lower electrode shielding plate 112 and rollerstand body 120 are rises integrally.

FIG. 19 shows view of support connecting member 216 from thin plateboard W's side. As shown in FIG. 19, connecting wire 220 c is connectedon the support connecting member through wire joint 218.

FIG. 20 shows the structure of positive electrode 102. Furthermore, 100c is a cap for dropping hole 100 b. Positive electrode 102 comprising301 has an anode case 102 a for housing plating metallic material likecopper ball, and grip 102 d is formed on side face of the anode case 102a, and hook 102 e is formed on lower part of the grip 102 a forattaching anode case 102 a to power supply rail 224 shown in FIG. 1. Theupper end of the grip 102 d reaches almost height of opening area 102 b.Also, four guide bars 102 c are attached at even intervals on theopening area 102 b (two bars are impossible to see because ofoverlapping in the back direction of drawing). The upper end of guidebars 102 c are extended until dropping hole 100 b for dropping metallicmaterial which is formed on the floor 100 a of the treatment tank mainbody 100.

It is needed to supply the anode case 102 a with metallic material whenkeeping on plating task. It is prevented that metallic material dropsinto the treatment tank main body 100 without housing in anode case 102a for existing of guide bar 102 c when dropping in dropping hole 100 b.

Also, it is needed to maintain by taking up the anode case 102 a whenkeeping on plating task. By the way, as metallic material is oftensupplied excessively to avoid lacking of metallic material (droppingmetallic material as brimming from dropping hole 100 b), metallicmaterial is prevented from dropping into the treatment tank main body100 by fitting guide tube in dropping hole 100 b formerly. However, itwas difficult to get rid of metallic material supplied excessively whenusing guide tube, and it takes a lot of trouble to remove the anode case102 a in maintenance. It becomes easy to remove the anode case 102 a inmaintenance, as metallic material supplied excessively from droppinghole 100 b is removed easily by using guide bars 102 c.

2. Board Dipping Device

The plating tank 2 in the embodiment described above has the boarddipping device for dipping the thin plate board W at dipping spot 2 a(FIG. 15). Referring to FIG. 13, the structure of board dipping devicewill be described as follows. Furthermore, FIG. 13A shows cross-sectionof board dipping device 600 indicating a condition when a board hasfallen at (x)-position shown in FIG. 14. FIG. 13B shows plane view ofthe board dipping device 600 shown in FIG. 13A from upside.

As shown in FIG. 13A, the board dipping device 600 is comprised oftreatment tank main body 60 which holds plating liquids for dipping thethin plate board W, board guide 62 for guiding the thin plate board Wwhen falling into the treatment tank main body 60, and air-bubbling tube68 which is generator of liquid current arranged outside the said boardguide 62.

As shown in FIG. 13A, the board guide 62 is comprised of lower guideplate 62 a arranged parallel spacing predetermined distance t, upperguide plate 62 b which is arranged like taper as widening toward upsidevertically and having slit 62 c of cutout, and current plate 62 d forpreventing liquid current which is occurred by air-bubbling fromspreading and weakening. Also, the board guide 62, as shown in FIG. 13A,is arranged as projecting the tip 62 e of upper board guide 62 b fromfluid level and dipping the said slit 62 c into plating liquids. FIG. 7shows perspective view of board guide 62.

The air-bubbling tube 68, which is generator of liquid current,discharges air upward based on air supply though pipe 66 shown in FIG.13A. Therefore, upward flow occurs as circumjacent plating liquids ofuprising air uprises and the plating liquids sectioned by current plate62 d flows from downside of current plate 62 d. Further, the uprisenplating liquids run through slit 62 c, and forms down flow between lowerguide plates 62 a. Thus, it becomes possible to guide and dip the thinplate board W along the board guide 62 smoothly. Further, as anexperimental result, it was more effective to guide smoothly whenarranging air-bubbling tube 68 at middle depth area in the treatmenttank main body 60 than arranging at same height as slit 62 c or at lowerarea of current plate 62 d. Also, as an experimental result, it was moreeffective to guide the thin plate board W smoothly when forming slit 62c on upper guide 62 b than forming it on lower guide 62 a.

The structure as the above-mentioned makes it easy to guide the thinplate board W smoothly because of generated liquid flow by generatorarranged outside the board guide 62, as the board guide 62 is projectingthe tip 62 e of upper board guide 62 b from fluid level and dipping thesaid slit 62 c into plating liquids.

Further, as shown in FIG. 13, the board dipping device is placed atdipping spot of board in the plating tank 2, and the air-bubbling tube68 is used as a generator of liquid current. However, it is possible touse jet nozzle 64 as a generator of liquid current as shown in FIG. 6Awhen it is desirable to enhance treatment effectiveness on though-holeof the thin plate board W and inside via hole, and when an acid-washclean treatment is performed in pre-treatment tank 1 where bubblingshould be avoided. In this case, jet flow is discharged nearly in ahorizontal direction toward slit 62 c from jet nozzle 64. Therefore, itbecomes possible to guide and dip the thin plate board W along the boardguide 62 smoothly, as flow is generated which passes through slit 62 cand directs downward between lower guides 62 b.

As an experimental result, it was more effective to guide the thin plateboard W smoothly when discharging a jet flow toward upper part R of slitas shown in FIG. 8 than discharging directly toward the slit. In FIG. 8,the jet flow is discharged upwardly to the level plane.

As shown in FIG. 6B, jet nozzle 64 is arranged at even intervals in atransporting direction of the transport hanger 15 (E-direction). Asshown in FIG. 6A, it is arranged fixedly at same height as cutout 62 cof the board guide 62.

Also, on the fluid level, it is possible to blow off by setting an airblower arranged outside the board guide 62, before discharged airthrough air-bubbling tube 68 forms bubbles on the fluid level. It isrealized by arranging the air blower as its air discharge directionfaces in a direction opposite to board guide. Therefore, it becomespossible to achieve a enough effect based on treatment liquids bypreventing the thin plate board W from acquiring bubbles on the surface.

Although, it is applied to plating tank in the embodiment describedabove, it is possible to apply to the other treatment tank like washing.

3. The Structure of the Surface Treatment Device and the TransportHanger

As shown in FIG. 14 and FIG. 15, the surface treatment device 300 is thesurface treatment device of so-called pusher type, and having guiderails 10-13 for transporting the transport hanger 15 which is holdingthe platy work such as a printed board, and arranged such that alongthese guide rails 10-13, the pre-treatment tank 1 of each type forprocessing before plating, plating tank 2 for electroplating, recoverytank 3 and water-washing tank 4 for processing after plating, unloadsection 5 for unloading the platy work, exfoliate tank 6 for separatingplating films (hanger restoring process), water-washing tank 7 forwater-washing the transport hanger 15 after separating, and load section8 for loading a board.

Rise-and-fall guide rails 10, 12 shown in FIG. 15 are guide rails whichrise and fall when loading or unloading the board W (such as printedboard), and when dipping the board W into various type of tanks (e.g.,plating tank 2, recovery tank 3 and water-washing tank 4, etc.). Fixedguide rails 11, 13 are guide rails fixed respectively for transportingthe transport hanger 15 which has fallen into plating tank 2, exfoliatetank 6.

Referring to FIG. 9, the structure of the transport hanger 15 will bedescribed.

As shown in FIG. 9, the transport hanger 15 has treating-object holdingmember 47 with plural clamps 48 for holding the treating-object W, slidemember 35 which contact slidably with guide rails such as fixed guiderail 11, and connecting members 44 for connecting such members. Copperand brass are used for the material of the slide member 35 andconnecting members 44.

The width L0 of treating-object holding member 47 is calculated based onthe width W0 of platy work W and clamping margin W1. For example, ifclamping margin W1 exists on both sides of platy work W (width W0) asshown in FIG. 9, the width L0 of treating-object holding member 47 iscalculated by formula: L0=W0−2×W1.

As shown in FIG. 10, a bearing 36 which has the gear 40 adjustingtogether with chain belt 39 (comprising the fixed guide rail transporter19 in FIG. 7) of one-way clutch type is fixed on the slide member 35.Therefore, the gear 40 which adjusts together with chain belt 39 on thefixed guide rail 11, 13 can rotate only in B-direction shown in FIG. 9when feeding forward.

The pusher contacting face 37 shown in FIG. 9 is a part contacted by thepusher 16, 21 (FIG. 11) of intermittent transporter 17, 22 which istransport means of the transport hanger 15

The nail-hooking part 32 of FIG. 10 is a part contacted by the transportnail 30 (FIG. 12) of positioning transporter 18 for transporting thetransport hanger 15. These transporters of the transport hanger 15 willbe described as follows.

4. Each Transporter for the Transport Hanger

The transport hanger 15 shown in FIG. 9 is transferred by intermittenttransporter 17, 22, positioning transporter 18, 23, fixed guide railtransporter 19, 24, and letting-off transporter 20, 25 in the surfacetreatment device 300 as follows.

First, intermittent transporter 17, 22 which is attached on top of therise-and-fall guide rails 10, 12 transport the transport hanger 15 pitchby pitch that is respectively placed at (c)-(f),(h)-(k) intermittentlyby using the pusher 16 a-d, 21 a-d (FIG. 11). FIG. 11 shows plane viewof intermittent transporter 17 on the rise-and-fall guide rail 10.

The positioning transporter 18 shown in FIG. 15 is arranged along thefixed guide rail 11. And the transport hanger 15 (FIG. 15), which hasfallen into dipping spot 2 a (board dipping position) at (x)-positionwhere is upside of the plating tank 2, is transferred to the fixed guiderail 11 and fed forward until (b)-position. And, the distance betweenplaty work W (thin plate board W) and the fore one placed at(a)-position (left side in FIG. 15) in the plating tank 2 is adjusted topredetermined width L1 (e.g. L1=5 mm).

FIG. 12 shows the structure of positioning transporter 18. Thepositioning transporter 18 shown in FIG. 12 is movable back and forth inX, Y-direction along rail which is arranged separately from the fixedguide rail 11, and having a transport nail 30 biased in Z-direction byspring in the condition shown FIG. 12A. Therefore, when transporting thetransport hanger 15, firstly pass through the nail-hooking part shown inFIG. 10 by shrinking the spring (condition shown in FIG. 12B). Afterthat, the transport hanger 15 is transferred to C-direction shown inFIG. 14, as the positioning transporter 18 moves in the oppositedirection (Y-direction of FIG. 12C) and the transport nail 30 hooks thenail-hooking part 32 of transport hanger 15. At this time, the movingspeed of the positioning transporter 18 is needed to be faster thanmoving speed of the fixed guide rail transporter 19 (i.e. the movingspeed of the chain belt 39) as to catch up a foregoing transport hanger15 that the fixed guide rail transporter 19 is transporting. Also, thestructure and the movement of positioning transporter 23 of exfoliatetank 6's side are same as positioning transporter 18 of plating tank 2'sside shown in FIG. 12.

The fixed guide rail transporter 19, 24 transports the transport hanger15 to C-direction of FIG. 14 which is fed forward by the positioningtransporter 18, 23, with keeping predetermined distance (L1 of FIG. 15).

The letting-off transporters 20, 25 transfer the transport hanger 15,which is transported by the fixed guide rail transporter 19, 24 until(g), (o), to (h), (f) position of the rise-and-fall guide rails 10, 12respectively (FIG. 14). Also, the structure and the movement ofletting-off transporter 20, 25 are same as positioning transporter 18shown in FIG. 12.

5. The Other Embodiment

Also, in the embodiment described above, although the upper (lower)board shielding plate and the upper (lower) electrode shielding plateare used as two shielding plates against the thin plate board W, it ispossible to add a further shielding plate between board shielding plateand electrode shielding plate.

Also, in the embodiment described above, although the upper boardshielding plate and the upper electrode shielding plate move up and downindependently, it is possible to let them move up and down integrally.

1. A plating tank for electroplating a platy work, comprising: atreatment tank main body for holding treatment liquids which is arrangedas extending in transporting direction of the platy work; a positiveelectrode; a spouter for spouting the treatment liquids to the saidplaty work from lateral side of the treatment tank main body; a restrictroller having a plural of rollers, wherein the rollers are attachedrotatably from upper part until lower part of the treatment tank mainbody and arranged consecutively in transporting direction of the platywork as sandwiching both sides of the platy work on moving inside thetreatment tank main body; a current shield for preventing from occurringcurrent concentration on the end of the platy work.
 2. The plating tankaccording to claim 1, wherein the said restrict roller is comprised of aplural of roller stand bodies which are having plural rollersvertically, and arranged in transporting direction of the said platingwork, and interval on the spouting position of the spouter betweenadjacent roller stand bodies are wider than the other intervals.
 3. Theplating tank according to claim 1, wherein a deviation preventing memberis placed at lower end area of the platy work where the spoutingposition of the spouter is placed as sandwiching both sides of the platywork on moving.
 4. The plating tank according to claim 1, wherein therollers are arranged at least one per predetermined unit area in aregion that the restrict rollers are arranged.
 5. The plating tankaccording to claim 1, wherein the said restrict roller is comprised of aplural of roller stand bodies which are having plural rollersvertically, and arranged in transporting direction of the said platingwork, and vertical intervals that the rollers of the restrict roller isarranged are range from 50 mm to 100 mm.
 6. The plating tank accordingto claim 1, wherein the said restrict roller is comprised of a plural ofroller stand bodies which are having plural rollers vertically, andarranged in transporting direction of the said plating work, and therollers placed over predetermined height differs the vertical positionmutually between the roller stand bodies.
 7. The plating tank accordingto claim 1, wherein the said current shield is comprised of a uppershielding plate for preventing from occurring current concentration onthe upper end of the platy work and/or a lower shielding plate forpreventing from occurring current concentration on the lower end of theplaty work.
 8. The plating tank according to claim 7, wherein the saidupper shielding plate and/or the lower shielding plate are comprised ofplural shielding plates arranged between the said platy work and thesaid positive electrode, and its overlap with the platy work is thesmaller, the closer to the platy work.
 9. The plating tank according toclaim 8, wherein the said plurality of shielding plates are formed in aunified manner and able to rise and fall.